Kenichi, a simple young man who lives with his wife in an apartment in Tokyo, is visited by his mother-in-law, Kaoruko, from his wife's family home, who is sightseeing in Tokyo. Kenichi begins to have naughty feelings for his mother-in-law, who is staying at Kenichi's apartment for three days and two nights, as she is a fragrant, ripe woman in her forties.
